1. Field of the Invention
The invention relates generally to a sensor the monitors a characteristic of a fluid, and, in particular, to technique for protecting such a sensor from liquid ingress.
2. Description of the Related Art
Systems that implement a sensor in communication with a flow of fluid, such as a gas, to monitor a characteristic of the flow of gas are well known. For example, it is known to provide a flow or pressure sensor in communication with a flow path to monitor a flow rate or pressure of gas through the flow path. In such systems, when liquid is present in the flow path, and the liquid is introduced to a conventional sensor, the accuracy of the sensor may be impeded, both in the short term and in the long term. In fact, in some instances, the introduction of liquid to a typical flow sensor may degrade the accuracy of the flow sensor to a degree such that readings taken by the flow sensor of the flow rate may become unusable.
In a device that employs a pressure or flow sensor to monitor the pressure or flow rate of gas along a flow path, such as a ventilator or pressure support system that provides a pressurized flow of gas to a patient along a flow path, the accuracy of the pressure or flow sensor being used may be relatively important to the operation of the device. Further, such a device may include a supply of liquid that is in communication with the flow path being monitored by the pressure or flow sensor. For example, in a ventilator or pressure support system, a humidifier for elevating a humidity level of gas may hold a supply of liquid in communication with the flow path. During use, due to various reasons, such as movement of the device, liquid from the supply of liquid held by the humidification chamber may reach the flow path being monitored by the pressure or flow sensor, and may enter the pressure or flow sensor. In such devices there exists a need for a system that substantially prevents the liquid from being introduced into the pressure or flow sensor, in order to preserve the accuracy of the sensor.